Fast idle adaptor for a diesel engine

ABSTRACT

There is provided an adaptor for use on a limiting speed governor of an internal combustion engine which governor includes a speed responsive mechanism for regulating the flow of fuel to the engine to stabilize the speed thereof, the mechanism being enclosed in a governor housing. The adaptor includes a housing secured to the governor housing and has therein a slide chamber which communicates with the interior of the governor housing. A slide is reciprocably received in the slide chamber for movement therein between a retracted and an extended position, and includes a biasing means coupled to the slide and extending inwardly of the governor housing for biasing the speed responsive mechanism in a direction to increase the fuel flow to the engine when the slide is in its extended position and which means is disengaged therefrom when in its retracted position. The biasing means is further resiliently compressible in resonse to operation of the speed responsive mechanism whereby the speed responsive mechanism is able to regulate the flow of fuel to the engine to stabilize the speed thereof. There are also provided means movably received in the control housing and engaged with the slide for selectively moving the slide between its retracted and extended positions.

[ July 24, 1973 United States Patent [1 1 Savage FAST IDLE ADAPTOR FOR A DIESEL ENGINE governor of an internal combustion engine which governor includes a speed responsive mechanism for regulating the flow of fuel to the engine to stabilize the speed thereof, the mechanism being enclosed in a gov- [76] Inventor: Czerney L. Savage, 5434 E. DuPont Rd., Fort Wayne, Ind.

Aug. 27, 1971 ernor housing. The adaptor includes a housing secured [22] Filed:

[21] Appl. No.: 173,496

[52] U.S. 123/140 J, tracted and an extended position, and includes a bias- [51] Int.

123/140 R F02d l/04 ing means coupled to the slide and extending inwardly of the governor housing for biasing the speed respon- [58] Field of Search...................... 123/140 J, 140 R sive mechanism in a direction to increase the fuel flow to the engine when the slide is in its extended position and which means is disengaged therefrom when in its "3/140 retracted position. The biasing means is further resiliently compressible in resonse to operation of the speed responsive mechanism whereby the speed responsive 123 140 mechanism is able to regulate the flow of fuel to the engine to stabilize the speed thereof. There are also provided means movably received in the control housing and engaged with the slide for selectively moving the slide between its retracted and extended positions.

0 4 l l 3 2 .l

[56] References Cited UNITED STATES PATENTS 2,669,983 2/i954 2,775,233 l2/l956 Bischoff.... 2,739,807 3/1956 Pope......... 2,986,291 5/1961 Schick Primary Examiner-Laurence M. Goodridge Assistant Examiner-Ronald B. Cox Attorney-Harold B. Hood [57] ABSTRACT There is provided an adaptor for use on a limiting speed 11 Claims, 8 Drawing Figures ma 622a.

FIGLI 2m F'IGB 8w 262 Patented July 24, 1973 2 Sheets-Sheet 1 I v 4 /44 0 2 7 0 u INVENTOR'. CZERNEY LJSAVAGE, BY ,M ,M*%

PRIOR ART FIGZ PRIOR ART ATTORNEYS.

Patented July 24, 1973 3,747,580

2 Sheets-Sheet INVENT'ORI CZEENE'Y L.SAVAGE,

BYM M 0.1km

ATTORNEYS.

FAST IDLE ADAPTOR FOR A DIESEL ENGINE BAQKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The present invention relates to a control device for use on a limiting speed governor of an internal combustion engine and more specifically to a fast idle adaptor which permits selectively varying the idle speed of such an engine without degradation of speed regulation thereof.

2. DESCRIPTION OF THE PRIOR ART Various forms of mechanical, limiting speed governors for use in controlling or regulating the speed of internal combustion engines are known in the prior art. In particular, such governors are extensively used for controlling the speed of diesel engines of the type used in heavy road vehicles. This type of governor generally incorporates a set of centrifugal weights which are coupled by a suitable mechanism to the engine to generate a first control force proportional to the speed of the engine. The governor further includes one or more regulating springs which generate a force counteracting the force generated by the centrifugal weight mechanism. In operation, the speed of the engine is regulated at its idle speed and maximum speed by the equilibrium between the forces generated by the governor weight mechanism and the regulating spring or springs. For all speeds between idle and maximum, the engine speed is controlled by a continuously variable throttle linkage which is controlled by the vehicle operator.

It frequently becomes necessary to allow such an engine to operate at elevated idle speed unattended for extended periods of time such as, for example, occur when the governor is used on a diesel engine of a truck type vehicle which is being loaded or unloaded or the truck is parked and the trucker resting or sleeping therein. It has been found that allowing the engine to idle at its normal regulated idle speeds for extended periods is detrimental to the engine. It is therefore necessary to provide a mechanism which enables increasing the idle speed of the engine. Various prior art devices have been proposed to achieve this result and typically comprise a hand actuated throttle which is affixed to the throttle control of the engine. However, these prior art throttle controls provide no meansfo r regulating the speed of the engine at the elevated speeds and therefore the speed ofthe engine when so controlled, is permitted to vary in response to the load thereon, this load varying frequently as the result of the activation and deactivation of accessory equipment on the vehicle. This, again, has been found to be detrimental to the engine.

SUMMARY OF THE INVENTION The invention in its broader aspects is an adaptor mechanism for use with a limiting speed governor on an internal combustion engine as described above. The mechanism comprises generally a control housing which is secured to the governor and has provided therein a slide chamber. The slide chamber communicates with the interior of the governor housing and a slide is reciprocally received therein for movement between a retracted and an extended position. There are means coupled to the slide and extending inwardly of the governor housing for biasing the speed responsive mechanism in a direction to increase fuel flow to the engine. The biasing means is engaged with the speed responsive mechanism when the slide is in its extended position and is disengaged therefrom when the slide is in its retracted position. The biasing means is resiliently compressible in response to operation of the aforementioned speed responsive mechanism to allow reduction of fuel flow to the engine thereby, and there are means movably received in the control housing which engage the slide for selectively moving the slide between its retracted and extended positions.

In one specific embodiment, the adaptor is provided with an interlock mechanism which prevents operation of the engine throttle when the adaptor is in use and, conversely, prevents operation of the adaptor when the throttle is moved from its idle position.

The control of the present invention therefore permits selectively controlling the regulated idle speed of the engine at a desired level.

In one embodiment the control is selectively, manually operated by means of a control cable and a suitable knob located at the operators station. In another embodiment, the control is activated by a diaphragm which is, in turn, selectively actuated by connecting the diaphragm to a source of pressure fluid such as compressed air which is associated with the engine via a fluid pressure control valve.

It is therefore an object of the present invention to provide a control mechanism for selectively altering the regulated idle speed of an internal combustion engine.

It is another object of the present invention to provide such a control which can be manually, selectively adjusted.

It is still another object of the present invention to provide such a control which cooperates with the limiting speed governor of an internal combustion engine to regulate the speed of the engine at a selected speed.

It is yet another object of the invention to provide such a control which is interlocked with the throttle linkage of the engine, whereby the operation of the throttle linkage and the governor control mechanism are mutually exclusive.

It is still another object of the invention to provide such a control which is simple in construction, reliable in operation, and economical to produce.

BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken inconjunction with the accompanying drawings, wherein:

FIG. 1' is a cutaway perspective view of a limiting speed governor with the governor control of the present invention affixed thereto;

FIG. 2 is a fragmentary top view of a portion of a limiting speed governor useful in explaining the operation of the invention; 7

FIG. 3 is an axial sectional view of one embodiment of the control of the invention;

FIG. 4 is an axial sectional view of another embodiment of the invention adapted for pneumatic operation;

FIG. 5 is a fragmentary perspective view of a portion of a limiting speed governor with the control of the present invention affixed thereto showing the operation of the interlocking mechanism of the control;

FIG. 6 is a perspective view showing details of a clamping stud used in the invention;

FIG. 7 is a fragmentary sectional view showing the buffer spring used on one type of governor control; and

FIG. 8 is an axial sectional view of another embodiment of the invention for use on a governor control which incorporates a buffer spring.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, there is illustrated a limiting speed governor, indicated generally at 10, which comprises an upper housing 12, lower housing 14, and shaft housing 16.

Journaled for rotation in the lower housing 14 is a governor input shaft 18. The left end of input shaft 18 (as viewed in FIG. 1) is coupled to the crank shaft of the engine (not shown) such that its speed of rotation is directly proportional to the speed of the engine. Fixedly secured to the input shaft 18 for rotation therewith is a spider 20 which is provided with oppositely disposed, bifurcated portions 22, 24, which carry centrifugal weight pivot shafts 26, 28. Pivotally carried on shafts 26, 28 are two sets of centrifugal weights 30, 32, which for clarity of illustration, are shown as single weights, weight 30 being a low speed or idle weight and weight 32 being a high speed or limiting weight. It will be observed that by reason of the shape and location of the pivot shafts 26, 28, the weights 30, 32 will pivot about the shafts 26, 28 as indicated by the arrows 34, 36 upon rotation of input shaft 18.

Slidingly received on input shaft 18 is a cylindrical slide collar 40 which is provided with enlarged, coaxial end portions 42, 44. Portion 42 engages the inwardly extending ends 46, 48 of weights 30, 32, respectively, whereby, as weights 30, 32 swing outwardly, the ends 46, 48 thereof will forcibly slide the slide collar 40 to the right (as viewed in FIG. 1). An operating lever 50 is journaled in housing portion 16 for rotation therein and has secured to its lower end a fork member 52 which partially encircles input shaft 18 in a position such that fork 52 is engaged by enlarged portion 44 of slide collar 40.

Fixedly secured to the upper end of operating shaft 50 is a lever arm 54 having orthogonally disposed arms 56, 58. Threadedly received in the distal ends of arm 56 is an adjusting screw 60 which extends therethrough and engages a spring tappet 62 which is slidably carried by a suitable bearing block 64 which is a part of housing portion 12. A spring assembly 66 compressibly engages tappet 62 and exerts a force thereagainst which tends to rotate arm 54 in a direction indicated by arrow 68.

As best seen in FIG. 2 spring assembly 66 includes a helical limiting spring 70 and a helical idle spring 72 disposed coaxially therein. A hollow tappet 74 engages limiting spring 70 anda slide tappet 76 is slidingly received within tappet 74 and engages idle spring 72. Tappet 76 is provided with an enlarged head portion 78 which is normally in a spaced apart relationship to the adjacent end of hollow tappet 74. It will be apparent that as lever arm 54 moves as indicated by arrow 80 it will first move slide tappet 76 to the left (as viewed in FIG. 2) compressing idle spring 72. As slide tappet 76 continues to move to the left, the enlarged head portion of 78 thereof will engage hollow tappet 74 and further movement oflever arm 54 as indicated by arrow 80 will tend to compress high speed spring 70. The purpose of these springs will be explained in more detail below.

Pivotally secured to the distal end of arm 58 of lever 54 by means of a suitable hinge pin 86 is a differential lever 88. End 90 of differential lever 88 is bifurcated to form a slot 92 therein which slidably receives an actuating pin 94 which in turn is fixedly secured to the distal end of actuating lever 96. Actuating lever 96 is fixedly secured to the throttle shaft 98 which is rotatably journaled in housing 12. To the end of throttle shaft 98 distal from actuating lever 96 is secured a throttle arm 100 for rotating same.

In operation, input shaft 18 rotates at a speed proportional to the speed of the engine (not shown) thereby spinning or rotating governor weights 30, 32, causing them to swing outwardly as indicated by arrows 34, 36, respectively. This movement is converted into linear motion of slide collar 40 which in turn pushes against fork 52 in a direction tending to rotate operating shaft 50 as indicated by arrow 102. Simultaneously, pressure is exerted against arm 56 of lever 54 by idle spring 72, this force tending to rotate operating shaft 50 in a direction opposite to arrow 102. Assuming that throttle arm 100 is not moved, it will be observed that the force exerted by idle spring 72 is transmitted to the differential lever 88 by means of arm 58 and hinge pin 86, this force tending to cause movement of end 104 of differential lever 88 in the direction indicated by arrow 106, this being the direction required to increase the flow of fuel, and thereby, the speed, of the engine. As the speed of the engine increases, the force exerted by weights 30, 32 increases until the force generated thereby is sufficient to overcome the force of idle spring 72. Any further increase in the speed of input shaft 18 will, by means of governor weights 30, 32, produce rotational movement of operating shaft 50 in a direction indicated by arrow 102. This rotational movement will in turn rotate lever arm 54, and correspondingly differential lever 88 in a direction opposite that indicated by arrow 106 thereby causing a reduction in the flow of fuel to the engine. It can be seen that with throttle arm 100 in a fixed position, specifically the idle position, the speed of the engine as established by the equilibrium between the forces exerted by governor weights 30, 32 and the force generated by idle spring 72. This is a normal idle condition and idle spring 72 is proportioned to exert in force sufficient to maintain the engine at a normal idle speed of, for example, 600

r.p.m.

When it is desired to increase the speed and power of the engine, throttle arm 100 is moved in a direction indicated by arrow 110. This movement is transmitted to differential lever 88 through its throttle shaft 98, actuating lever 96 and pin 94. This movement will cause pivotal movement of differential lever 88 about hinge pin 86 and, correspondingly, will cause end 104 of differential lever 88 to move in the direction indicated by arrow 106 thereby increasing the flow of fuel to the engine. The speed of the engine will correspondingly increase thereby increasing the speed of input shaft 18. When the engine is operating in its normal and allowable speed range, further movement of centrifugal weights 30, 32 is resisted by high speed spring 70, thereby allowing the speed and power of the engine to be controlled manually by throttle lever 100. However, as the engine approaches its maximum permitted speed, the force of governor weights 30, 32 will become sufficient to overcome the force exerted by high speed spring 70. When this occurs, any further increases in the speed of the engine and input shaft 18 will cause governor weights 30, 32 to rotate, operating shaft 50 in the direction indicated by arrow 102, which movement will, as described above, move end 104 of differential lever 88 in a direction opposite to that indicated by arrow 106 thereby tending to reduce the flow of fuel to the engine to stabilize the speed thereof.

It is thus seen that the governor mechanism as described above controls or regulates the speed of the engine to which it is affixed at a predetermined idle speed by means of idle spring 72 and limits the maximum speed thereof by means of high speed spring 70. For all speeds of the engine between idle speed and maximum speed, the speed of the engine is controlled by manual mechanism as described is only illustrative of the operation of a typical governor mechanism and that many variations therein have been devised and are in use. However, in all of these mechanisms there is included a suitable speed responsive mechanism such as the centrifugal weights 30, 32, and one or more regulating springs such as idle spring 72 and limiting spring 70 which are operatively coupled to a fuel control mechamsm.

Referring now to FlGS. 1-3, there is illustrated a governor control mechanism 120,which comprises generally a housing 122, which includes a lever block 124 and an externally threaded mounting stud 126.

Lever block 124 is generally rectangular and is provided with a slot 128. An activating lever 130 is received'in slot 128 and secured for pivotal movement therein with a suitable hinge pin 132.

Block 124 is further provided with a threaded hole 134 which threadedly receives stud 126. Stud 126 is provided with a stepped diameter, cylindrical slide chamber 138 which extends axially therethrough and communicates with slot 128. Slidingly received within slide chamber 138 is a slide 140 having an enlarged head 142 which is abuttingly engaged by actuating lever 130. Frictionally fitted to the opposite end of slide 140 is a helical compression spring 144 which functions as a biasing means as explained below and which is slidably movable with slide 140 and extends outwardly of end 146 of stud 126.

The end of stud 126 adjacent block 122 is fitted with a lock nut 148 which secures stud 126 against rotation of movement with respect to block 124. Fitted to the end of actuating lever 130 distal pin 132 is a cable clamping stud 150 which extends through actuating lever 130 and is secured by means of a threaded fastener 152. Each of the ends of stud 150 is provided with a hole 154, 156, respectively, and a pair of set screws 157, 158 are threadedly received into the opposite ends of stud 150, whereby, an operating cable can be adjustably received within hold 156 and clamped with set screw 158 and an interlock rod (as will be explained below) received and clamped in hole 154 by means of set screw 157.

Referring again to FIG. 1, governor control 120 is shown in its installed position on governor 10. It can be seen that in its installed position, governor control 120 is secured to housing portion 12 of governor 10 with slide chamber 138 thereof communicating with the interior of the governor housing and with helical spring 144 extending inwardly thereof and abuttinglyengaging end 104 of differential lever 88. Preferably, the securement of governor control is effected by providing the governor housing portion 12 with a threaded aperture 160 therein. Frequently the governor housing is provided with a threaded hole 160 which is fitted with an adjustable idle screw whereby no modification of the governor is necessary. Stud 1126 is adjustably threaded into aperture 160, the depth of insertion providing an convenient method of settng the operating range of the control and secured with a suitable lock nut 162 (FIG. 5). With actuating lever in the position indicated in solid lines in FIG. 5, slide and helical spring 144 of governor control 120 are freely slidably movable within slide chamber 138 whereby compresson spring 144 exerts no force against differential lever 88, but rather, is movable therewith. However, when actuating lever 130 is moved into the position indicated in the dotted lines (FIG. 5), lever 130 will abuttingly engage slide 140 forcing compression spring 144 into resilient, compressible engagement with end 104 of differential lever 88. From the aforementioned description of the operation of the governor 10, it will be apparent that compression spring 144 will now exert a force against differential lever 88 in a direction tending to increase the flow of fuel to the engine. It will further be apparent that as the speed of the engine increases, the force exerted by governor weights 30,32 will increase until the force exerted thereby is sufficient to overcome the compressive force of spring 144 at which time any further increase in the speed of the engine will enable the governor weights 30, 32 to force differential lever 88 in a direction opposite that indicated by arrow 106 thereby reducing and regulating the flow of fuel to the engine to stablize the speed thereof. It will further be apparent that the force against end 104 of differential lever 88 exerted by compression spring 144 will be proportional to the inward movement of slide 140 which in turn is proportional to the movement of actuating lever 130.

The governor control mechanism of this invention thus provides a meansfor adjustably controlling the speed of an internal combustionengine by resiliently biasing the governor mechanism thereon to stabilize at engine speeds between normal idle speed thereof up to a predetermined maximum speed determined by the maximum compressive force of compression spring 144. It is further apparent that the governor control mechanism, rather than overriding the operation of the governor, cooperates with the mechanism thereof to enable the governor to function in its normal manner at speeds intermediate the idle and maximum speeds of the engine whereby the speed of the engine can be reg ulated and thereby stabilized at intermediate speeds.

To enable actuation of the governor control mechanism, there is provided an elongated control cable 170 which is clampingly secured to stud at one end and is provided with a suitable knob 172 at its other end, knob 172 being located at a convenient operators position such as, for example, in the cab of a vehicle.

However, it is further apparent that spring 144 exerts a force against differential lever 88 which opposes the force exerted thereagainst by centrifugal weights 30, 32 and that this force is in parallel with or additive to the force exerted by high speed spring 70. For this reason, when the governor control is activated, the maximum speed at which the engine will be permitted to operate will be increased in proportion to the force exerted by the compression spring 144. Thus, if the governor control is activated and the throttle lever 100 is moved into a position to operate the engine at its maximum speed, the governor control will permit the engine to exceed its normal operating limits. It is therefore necessary to provide the governor control with an interlock with throttle lever 100 whereby the operation of governor control 120 will exclude operation of throttle lever 100, and conversely, operation of throttle lever 100 will prevent activation of the governor control.

This interlock mechanism is illustrated in FIG. and

- comprises an interlocking cam 180 which is pivotally secured to the governor housing portion 12 with a suitable mounting bracket 182 by means of threaded fasteners 184, 186. Throttle lever 100 is provided with a detent pad 176 at its distal end and cam 180 is positioned with respect to detent pad 176 such that when cam 180 is in the position indicated in solid lines in FIG. 5, detent pad 176 passes thereover and throttle lever 100 is umimpeded thereby and can be operated in a normal manner. When interlock cam 180 is in a position indicated in dotted lines in FIG. 5, cam 180 engages detent pad 176 preventing movement thereof. Conversely, when interlock cam 180 is in the position indicated in solid lines, and throttle lever 100 is moved from an idle position, detent pad 176 will overlie cam 180 preventing movement thereof.

Coupled between end 188 of interlock cam 180 and stud 150 is a control link 190 which functions to move interlock cam 180 from its solid line position to its dotted line position whenever governor control mechanism 120 is activated, and conversely, functions to prevent activation of governor control mechanism 120 whenever throttle lever 100 is moved out of its idling position. It can thus be seen that the interlock mechanism positively prevents the simultaneous actuation of throttle lever 100 and governor control mechansim 120 whereby governor control mechanism 120 cannot cause over speeding of the engine.

Referring now to FIG. 4, there is illustrated a governor control mechanism 200 in accordance with the present invention which is adapted to operate in response to pressure fluid such as compressed air. The control 200 includes a housing 202 which is provided with a cylindrical diaphragm chamber 204 therein. A flexible diaphragm 206 of fluid impervious material such as rubber or coated fabric is disposed within diaphragm chamber204 dividing it into two chambers 208, 210. Chamber 210 is provided with a vent orifice 212 which communicates between chamber 210 and the atmosphere and a fluid pressure port 214 is formed in housing 202 and communicates with chamber 208. Port 214 is of stepped diameter and the large diameter portion thereof is provided with suitable threads 216 which receive conventional fluid coupling fittings (not shown). Received in housing 202 is an externally threaded stud 218 which has a hollow bore 220 therein. Slidably received within bore 220 is a helical compression spring 222 similar to compression spring 144 described above. Frictionally secured to one end of compression spring 222 is a tappet 224 which is abuttingly engaged at its distal end by diaphragm 206. Tappet 224 has an enlarged head 226 and a helical compression spring 228 is fitted between enlarged head 226 and a suitable shoulder 230 of diaphragm chamber 210.

Frictionally fitted to end 232 of helical spring 222 is a push rod 234 which is adapted to engage the fuel control lever or differential lever ofa governor such as governor 10 described above.

It can now be seen that when pressure fluid is applied to the left side of diaphragm 206 (as viewed in FIG. 4) pressure fluid will force diaphragm 206 to the right moving compression spring 222 and push rod 234 correspondingly. This movement will, as above, bias the fuel control lever of the governor (not shown) to increase the flow of fuel to the engine and at the same time is resiliently compressible whereby the speed responsive mechanism in the governor can move push rod 234 to the left to reduce the flow of fuel to the engine when the engine speed exceeds a predetermined value.

The control of pressure fluid to diaphragm 206 can be controlled either by an on-off fluid control valve in which case the governor control will function to regulate the engine speed at a single predetermined speed. In the alternative, pressure fluid can be applied to diaphragm 206 by means of a suitable pressure fluid control valve (not shown) whereby the pressure applied to diaphragm 206 can be varied to enable the governor control 200 to regulate the speed of the engine at any desired speed within its operating range.

It will be apparent that the pressure fluid actuated governor control can also be provided with a throttle lever interlock as described above which interlock can be energized by separate diaphragm assembly in a well known manner. In the alternative, control 200 can be provided with an additional push rod which can be coupled to an interlock cam such as cam 180 described above.

Referring now to FIG. 7, there is illustrated a portion ofa governor control 10a identical to that illustrated in FIG. 1 which further includes a compression or buffer spring 250 which is frictionally retained in a cavity 252 which is formed axially in an idle adjusting screw 254. Idle spring 254 is threadingly received in housing 12a via a suitable threaded hole 256 in a position wherein buffer spring 250 engages end 1040 of differential lever 88a when the governor throttle lever (not shown) is in its idle position. Buffer spring 250 functions as a resilient stop which compressively engages end 104a of differential lever 88a when the engine to which the governor 10a is affixed is idling, whereby, differential lever 88a is permitted to move in the direction indicated by arrow 258 in response to the force generated by the centrifugal weights of the governor assembly (not shown) when the speed of the engine begins to exceed its predetermined idle speed. Thus, buffer spring 250 permits additional control of the flow of fuel to the engine at idle speed by permitting the centrifugal weights of the assembly to further reduce the flow of fuel to the engine. By properly adjusting the idle screw 254, it is possible to eliminate cyclical variations or roll in the engines idle speed.

In FIG. 8 there is illustrated another embodiment of the adaptor mechanism or control a which is adapted for use on governor controls which are fitted with a buffer spring assembly as illustrated in FIG. 7. Control mechanism 120a again comprises a housing 122a which includes a lever block 124a and an externally threaded mounting stud 126a. Block 124a is provided with a threaded hole 134a which threadedly receives stud 126a and extending axially through stud 126a is a stepped diameter, cylindrical slide chamber 138a. Frictionally retained in end 260 of slide chamber 138a is buffer spring 250a which is identical to buffer spring 250 illustrated in FIG. 7. Slidingly received in the opposite end of slide chamber 138a is a slide 140a which extendsoutwardly therefrom and is engaged by an actuating lever (not shown). Also slidingly received in slide chamber 138a is a helical compression spring or biasing means 144a, which is abuttingly engaged by slide 140a and movable therewith. A stepped diameter engaging pin 262 has an enlarged head portion 264 which is slidingly received in slide chamber 138a as shown and abuts helical spring 144a, pin 262 also having'an elongated stem 266 which is slidingly received through buffer spring 250a. Slide 140a, helical spring 144a, and engaing pin 262 are all conjointly movable axially of slide chamber 138a as indicated by arrows 270 in response to movement of the actuating lever (not shown).

To install the control 120a on the governor assembly 10a, the buffer spring 250 and idle adjusting nut 254 thereof are first removed and the assembly 120a substituted therefor, threaded stud 126a being threadedly received in hole 256 of the governor 10a. With slide 140a, helical compression spring 144a, and engaging pin 262 in the retracted position, i.e., to the right as viewed in FIG. 8, the control assembly 120a is threaded into hole 256 until buffer spring 250a compressively engages end-104a of differential lever 88a. Thus assembled, governor 10a functions in its normal manner. However, when slide 140a, and correspondingly, helical spring 144a and engaging pin 262 are moved to the left (as viewed in FIG. 8) by means of the actuating lever, engaging pin 262 will be forced into engagement with end 104a of differential lever 88a. By reason of helical compression spring 144a, engaging pin 262 will be resiliently movable in response to the forces generated by centrifugal weights and spring assembly of the governor control 10a (not shown). As described above in reference to FIGS. 1 and 5, it will again be apparent that compression spring 144a will exert a force against differential lever 88a (now by means of engaging pin 262), in a direction tending to increase the flow of fuel to the engine. Similarly, as the speed of the engine increases, the force ex- .erted by the governor weights will increase until the reducing and regulating the flow of fuel to the engine to stabilize the speed thereof. Because the force exerted by compression spring 144a acts against the force developed by the centrifugal weight, movement of the slide 140a, compression spring 144a, and engaing pin 262 into compressive engagement with differential lever 88a will increase the regulated idle speed of the engine without in any way interferring with the ability of the governor 10a to control the speed thereof.

As with the previous embodiment, the control 120a may be provided with an interlock mechanism such as that described in reference to FIGS. 1 and 5 to insure that the operation of the control 120a and the governor a are mutually exclusive. Further, because the assembly 1200 is received within threaded hole 256 which is already provided in housing 12a, no modifications of the housing 12a are required for installing the control a.

In a working embodiment of the invention, a helical compression spring was used with a spring constant of 31 to 32 pounds per inch and the movement of the slide was equal to about one-half inch. With this spring constant and slide movement, the control or adapter enabled increasing the idle speed of the engine from 600 rpm. to 1,000 rpm.

While there have been described. above the principles of this invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of the invention.

What is claimed is:

1. For use with a limiting speed governor for an internal combustion engine which governor includes a speed responsive mechanism for regulating the flow of fuel to and thereby the speed of, the engine, the mechanism being enclosed in a governor housing, a governor control mechansim comprising a control housing secured to the governor housing and having a slide chamber therein, said slide chamber communicating with the interior of said housing, a slide reciprocally received in said slide chamber for movement between a retracted and an extended position, means coupled to said slide and extending inwardly of said governor housing and engaging the speed responsive mechanism when said slide is in said extended position for biasing the speed responsive mechanism in a direction to increase fuel flow to the engine when said slide is in said extended position and being disengaged therefrom when said slide is in said retracted position, said biasing means being resiliently compressible in response to operation of said speed responsive mechanism to reduce fuel flow to the engine, and means movably received in said control housing and engaged with said slide for selectively moving said slide between said retracted and extended positions.

2. The control of claim 1 wherein the speed responsive mechanism of the governor includes a leveroperatively coupled to a fuel metering device, said biasing means being engaged with said lever.

3. The control of claim 2 wherein said biasing mean includes a helical compression spring secured to one end of said slide, the opposite end of said helical spring abutting said lever at a point displaced from the pivot thereof, whereby, when said slide means is moved from said retracted to said extended position, said spring moves said lever in a direction to increase the fuel flow to the engine.

4. The control of claim 3 wherein said lever is a differential lever and said speed responsive mechanism includes a set of centrifugal governor weights and at least one low speed regulating spring, said lever being movable in a direction to increase said fuel low in response to movement of said governor weight and movable in a direction to reduce said fuel flow in response to said spring, said biasing means being engaged with said lever to exert a force additive to the force exerted by said spring.

5. The control of claim 2 wherein said biasing means further includes a push pin having one end secured to the distal end of seaid helical spring and its opposite end in abutting engagement with said lever, said pushpin being reciprocably movable in response to movement of said slide.

6. The control of claim 1 wherein said moving means includes a lever pivotally secured to said control housing in abutting engagement with said slide, and a control cable coupled to the end of said lever distal said pivot, whereby movement of said control cable causes pivotal movement of said lever and corresponding sliding movement of said slide.

7. The control of claim 2 wherein said moving means includes a fluid actuated diaphragm and a pressure fluid control switch, said diaphragm being connected to a source of pressure fluid through said fluid control switch, said diaphragm being connected to said slide, whereby, actuation of said fluid control switch causes movement of said diaphragm in a first predetermined direction and corresponding movement of said slide from said retracted to said extended position.

8. The control of claim 1 wherein said control housing includes means adjustably securing said housing to said governor housing, the controlling range of 'said control being determined by the adjustment of said adjusting means.

9. The control of claim 8 wherein said securing means comprises a threaded stud, said slide chamber being in said stud.

10. For use on a governor which further includes a manually adjustable control lever for controlling the speed of the engine the control of claim 1 further com prising means for interlocking the movement of said slide means with the movement of the manually adjustable lever for mutually exclusive operation.

11. The control of claim 10 wherein said interlocking means includes a cam secured to said governor housing for pivotal movement between first and second positions, and linkage means coupling said cam to said moving means for synchronizing the movement thereof, said cam being disposed in said first position when said slide is in said extended position, and engaging a portion of said manual lever whereby said cam prevents movement of said lever, said cam being in said second position when said slide is in said retracted position, said cam being engaged by a portion of said manual lever when in said second position whereby said cam is prevented from movement by said manual lever. a 

1. For use with a limiting speed governor for an internal combustion engine which governor includes a speed responsive mechanism for regulating the flow of fuel to and thereby the speed of, the engine, the mechanism being enclosed in a governor housing, a governor control mechansim comprising a control housing secured to the governor housing and having a slide chamber therein, said slide chamber communicating with the interior of said housing, a slide reciprocally received in said slide chamber for movement between a retracted and an extended position, means coupled to said slide and extending inwardly of said governor housing and engaging the speed responsive mechanism when said slide is in said extended position for biasing the speed responsive mechanism in a direction to increase fuel flow to the engine when said slide is in said extended position and being disengaged therefrom when said slide is in said retracted position, said biasing means being resiliently compressible in response to operation of said speed responsive mechanism to reduce fuel flow to the engine, and means movably received in said control housing and engaged with said slide for selectively moving said slide between said retracted and extended positions.
 2. The control of claim 1 wherein the speed responsive mechanism of the governor includes a lever operatively coupled to a fuel metering device, said biasing means being engaged with said lever.
 3. The control of claim 2 wherein said biasing mean includes a helical compression spring secured to one end of said slide, the opposite end of said helical spring abutting said lever at a point displaced from the pivot thereof, whereby, when said slide means is moved from said retracted to said extended position, said spring moves said lever in a direction to increase the fuel flow to the engine.
 4. The control of claim 3 wherein said lever is a differential lever and said speed responsive mechanism includes a set of centrifugal governor weights and at least one low speed regulating spring, said lever being movable in a direction to increase said fuel low in response to movement of said governor weight and movable in a direction to reduce said fuel flow in response to said spring, said biasing means being engaged with said lever to exert a force additive to the force exerted by said spring.
 5. The control of claim 2 wherein said biasing means further includes a push pin having one end secured to the distal end of seaid helical spring and its opposite end in abutting engagement with said lever, said push pin being reciprocably movable in response to movement of said slide.
 6. The control of claim 1 wherein said moving means includes a lever pivotally secured to said control housing in abutting engagement with said slide, and a control cable coupled to the end of said lever distal said pivot, whereby movement of said control cable causes pivotal movement of said lever and corresponding sliding movement of said slide.
 7. The control of claim 2 wherein said moving means includes a fluid actuated diaphragm and a pressure fluid control switch, said diaphragm being connected to a source of pressure fluid through said fluid control switch, said diaphragm being connected to said slide, whereby, actuation of said fluid control switch causes movement of said diaphragm in a first predetermined direction and corresponding movement of said slide from said retracted to said extended position.
 8. The control of claim 1 wherein said control housing includes means adjustably securing said housing to said governor housing, the controlling range of said control being determined by the adjustment of said adjusting means.
 9. The control of claim 8 wherein said securing means comprises a threaded stud, said slide chamber being in said stud.
 10. For use on a governor which further includes a manually adjustable control lever for controlling the speed of the engine the control of claim 1 further comprising means for interlocking the movement of said slide means with the movement of the manually adjustable lever for mutually exclusive operation.
 11. The control of claim 10 wherein said interlocking means includes a cam secured to said governor housing for pivotal movement between first and second positions, and linkage means coupling said cam to said moving means for synchronizing the movement thereof, said cam being disposed in said first position when said slide is in said extended position, and engaging a portion of said manual lever whereby said cam prevents movement of said lever, said cam being in said second position when said slide is in said retracted position, said cam being engaged by a portion of said manual lever when in said second position whereby said cam is prevented from movement by said manual lever. 